It was simply hidden from us by modern radio.
Satellite radio, Amazon Music, and Spotify brough it back to us, and I am forever grateful. Couldn't tell you the last time I turned on AM or FM radio on purpose.
That's a fact, and probably planned that way. I would add Youtube to the list as well. Satellite radio would introduce me to various singers / bands, but then after searching them further on Youtube, I was missing out on some good music. Blackberry Smoke comes to mind as well as The Steeldrivers on the bluegrass side with Chris Stapleton as lead vocals. I'd rather hear CS back then vs todays stuff he sings. Not sure it classifies as country, but Oliver Anthony had a good run bypassing the normal radio route, and using Youtube. It was funny during an interview where he said music today for radio had to be a certain way like it was an OSHA standard or something. lol